Bone anchor inserter with retractable shield

ABSTRACT

A medical stapler and screw inserter device is disclosed herein wherein the medical instrument is formed in a non-linear or “C” or “V” shaped conformation. The non-linear shape allows the physician to accomplish a per vaginal anchor or screw insertion into a patient&#39;s pubic bone, while locating the triggering hand outside of the vagina of the patient and employing a pulling force on the inserter/stapler, against the pubic bone of the patient. In addition, the weight of a patient&#39;s body may be used to counterweight the recoil effect to minimize stapler recoil during ejection of a staple from the stapler into a patient. Bone anchor screws and a related bone screw driver and a method of inserting it into the pubic bone through the vagina are also described for per vaginal bladder neck suspension procedures.

RELATED APPLICATION

The present application is a continuation of U.S. application Ser. No.08/733,798, filed Oct. 18, 1996, now U.S. Pat. No. 5,972,000; which is acontinuation-in-part of U.S. application Ser. No. 08/622,598, filed Mar.26, 1996, now U.S. Pat. No. 5,807,403; which is a continuation of U.S.application Ser. No. 08/150,517, filed Nov. 10, 1993, now U.S. Pat. No.5,520,700; which claims priority to Israeli Patent Application No.103,737, filed Nov. 13, 1992. The present application also claimspriority to Israeli Patent Application No. 127,978, filed Jan. 8, 1999;U.S. Patent Application Ser. No. 09/287,867 filed Apr. 7, 1999(pending), U.S. Provisional Application Ser. No. 60/012,205 filed Feb.23, 1996; and U.S. Provisional Application Ser. No. 60/005,348 filedOct. 18,1995. The present application claims the domestic and foreignpriority benefits of these prior applications. These prior applicationsand their contents are herein incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a bone anchor, bone anchor screw, andan inserting device for use in medical applications, and particularly inmedical suturing. The invention is especially useful in treating femaleurinary stress incontinence, although it can be utilized with othermedical applications as well.

BACKGROUND OF THE INVENTION AND DESCRIPTION OF THE PRIOR ART

Urinary stress incontinence, i.e., the inability to control urinationfrom the bladder, is a distressing problem for more than ten percent ofelderly women as well as for many young women. This condition frequentlyarises in the following manner: in a normally anatomically positionedbladder, the proximal urethra and the bladder are in pressure continuitywith the abdominal cavity, so that an increase in abdominal pressure istransmitted both to the bladder and to the proximal urethra, resultingin normal continence. However, particularly among elderly women, thebladder and the proximal urethra tend to descend from their normalanatomic positions such that the bladder neck and proximal urethra moveaway from the posterior wall of the pubic bone. When this occurs, theproximal urethra is no longer in pressure continuity with the abdominalcavity; therefore, an increase in intra-abdominal pressure (e.g. bylaughing or coughing) results in an increase in intravesical pressure,but no change in the urethral closing pressure, thereby producingso-called stress incontinence. It also appears that as the bladderdescends, the urethra becomes shorter and curved, so that its radialtonic muscle contraction is reduced, contributing to incontinence.Another pathology may arise from urethral sphincteric damage.

The surgical treatment for stress incontinence involves bladder necksuspension. One treatment is by an open surgical operation, involving anincision in the abdominal wall and/or anterior vaginal wall, toreposition and suspend the bladder and proximal urethra to their normalanatomic positions. This is done by suspension of the bladder neck andperiurethral tissue to the posterior wall of the pubic bone. In anothersurgical procedure, the bladder neck is elevated by suspension of suturethreads passing, with the aid of long needles, from both sides of theurethra and the bladder neck to the lower abdominal fascia or superiorpubic bone ramus.

In prior patent application Ser. No. 08/150,517 filed Nov. 10, 1993 andits continuing application (the disclosures of both of which are herebyincorporated by reference) the inventors have disclosed apparatus andmethod(s) which allows treatment of stress incontinence by incisionlessper vaginal bladder neck suspension. As disclosed therein, an inserterdevice can be utilized for ejecting and implanting a staple or boneanchor through the vaginal tissue to enter the pubic bone. In anotherembodiment, as further discussed hereafter, an inserter device can beused to install a bone anchor by screwing the bone screw into the pubicbone, with or without vaginal incision. The suture thread that issecured to the bone anchor, staple or bone screw, suspends the bladderneck and the periurethral tissue to the posterior wall of the pubicbone.

It has been found, however, in stapler devices, and especially thosethat require high impact for bone implantation, that the ejection of thestaple from the device causes the stapler to recoil. As is apparent frombasic physics, the action of ejecting the staple from the stapler isassociated with a reaction force which forces the inserter/stapler, andthe hand of the individual (the physician) implanting the same, to movebackwards. As a result, the physician must take this recoil into accountand use force to firmly press the stapler against the pubic bone toensure that the bone anchor is properly and effectively ejected andimplanted. Anyone familiar with carpentry-type staple guns is familiarwith this recoil. If pressure is not placed over the head end of thestapler, and the surface into which the staple is driven is hard (as inthe case of bone), the staple will not be fully implanted, but, rather,the user's hand will recoil. The medical stapler should also be heldperpendicular to the bone surface. The stapler must be held in thatposition with the stapler held firmly during and through the ejectionprocess so that the stapler does not shift its position as a result ofthe recoil. Otherwise, undue movement of the stapler because of recoilcan result in a staple being ejected in an incorrect orientation, orincompletely ejected into the bone of the patient. This problem isespecially apparent where the material into which the staple is ejectedis bone and the physical confines of the space where the medicalphysician's hands are working is limited, i.e., within a vagina.

Similarly, where the inserter is a screwdriver type and the anchor is ascrew type anchor, unless a hole is pre-drilled in the insertion site,constant firm pressure must be applied through the axis of the anchor(perpendicular to the pubic bone) to assist the self tapping property ofthe anchor to facilitate insertion during screwing. The medicalscrewdriver type inserter must, therefore, be held in the correctposition relative to the patient's anatomy through the insertionprocess.

A purpose of the present invention is to provide leverage, whichfacilitates a constant pressure at the insertion site to minimize theeffect of this recoil, increasing the ease of use of an inserter devicein a medical procedure (whether a pusher or impact type inserter, or ascrew inserter), and increasing an inserter device's effectiveness. Thisfurthers the self-tapping property of the bone anchor, whether it be animpact type or screw type anchor. A screw type inserter device increasesthe ease of use of an inserter device in a medical procedure andincreases the present stapler device's effectiveness.

A further purpose of the present invention is to provided leverage inthe per vaginal insertion of a bone anchor into the pubic bone. Thepresent invention allows the physician to employ a pulling forceperpendicularly against the pubic bone of the patient, and toconveniently do so with one hand. The leverage, degree of accuracy andease of insertion are believed to be significantly enhanced by thepresent invention.

In one embodiment, the invention relates to per vaginal bone screwinsertion without drilling a hole in the bone by use of a non-linear orC-shaped inserter having a rotating intravaginal head for per vaginalbone screwing with or without vaginal wall incision. An additionalpurpose of the present invention is to provide a screw type bone anchorand related device and procedure for per vaginal incisionless or minimalincision bladder neck suspension.

SUMMARY OF THE INVENTION

The present invention addresses the difficulties experienced in theprior art by providing a “C”, “V” or other non-linear insertion shapeddevice for use in medical applications, and especially, per vaginalinsertions of anchors of any type into the pubic bone of a patient. Theinsertion device, which may be rigid or flexible, is positioned duringuse so that force may be applied through the axis of the anchor. Theweight of a patient can contribute to the force applied by the physicianto firmly press the device against the patient's anatomy, so as tominimize the effects of the problems normally associated with recoil.Although the present device is directed toward a stapler device for useto eject a staple type bone anchor, it will be appreciated that thepusher/driver portion of the device can alternatively be used to inserta screw type bone anchor and will be useful in other applications aswell.

Accordingly, it is an object of the present invention to provide aninsertion device which inirnizes recoil during ejection of a bone anchorinto bone.

It is further an object of the present invention to provide an insertiondevice which minimizes recoil during per vaginal insertion of a boneanchor into the pubic bone and otherwise allows constant pressure to beapplied during the per vaginal insertion of self-tapping anchors intothe pubic bone.

It is a further object of the present invention to provide a devicewhich facilitates additional pressure to be applied to the insertionsite beyond the direct pushing pressure applied by the physician in thecase of a linear inserter held in place in the vagina by the physician'shand. With the present inserter, the physician's hand is used to pullthe inserter against the resistive force of the pubic bone, therebyforcing the anchor tip to penetrate the bone cortex. It is far easier toinsert a bone anchor, staple or screw with the hands external to thevagina and by use of the pulling force perpendicular to the bonesurface.

It is further an object of the present invention to provide an inserterdevice for medical applications which improves the accuracy andeffectiveness of anchor insertions.

It is further an object of the present invention to utilize the physicalpulling force on the inserter to further fixate the anchor tippenetration force perpendicular to the bone surface and in line with thephysician pulling force.

It is further an object of the present invention to utilize at least aportion of the weight of a patient's body to maintain a bone anchor orscrew inserter in firm contact with the patient during insertion of abone anchor or screw into the patient's bone.

It is a further object of the present invention to use at least aportion of the weight of a patient as counter balancing leverage againstthe recoil of a bone anchor/staple/screw being inserted into the bone ofa patient.

It is further an object of the present invention to provide an improvedinserter device for inserting bone anchors, staples and/or screws inmedical procedures.

It is further an object of the present invention to provide an improvedbone anchor inserter for use in and to facilitate medical applications.

It is further an object of the present invention to provide improvedbone anchors and bone anchor inserters.

It is further an object of the present invention to provide improvedbone anchors and bone anchor inserters for treatment of female urinarystress incontinence and medical applications.

It is further an object of the present invention to provide an improvedmethod for treatment of urinary stress incontinence.

It is further an object of the present invention to provide an improvedmethod for treatment of urinary stress incontinence including pervaginal bone anchor insertion into the pubic bone. These bone anchorsare either in the form of staples or screws. The bone anchor has eithera non-linear (e.g. a “C” or “V” shape) or linear shape and is operatedeither by an impact or by a rotational movement to insert or screw abone anchor, staple or bone screw into the bone with or without vaginalwall incision.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a left side view of a stapler or pusher/impact type boneanchor inserter, in accordance with the present invention, with a frontview of a loading key shown as well.

FIG. 1b is a bottom, back, and left side perspective view (on adifferent scale) of the stapler or pusher/impact type bone anchorinserter of FIG. 1a.

FIG. 1c is a right cross-sectional view of a screwdriver-type boneanchor inserter for rotational insertion of bone screws.

FIGS. 1d(1)-1 d(6) are front views of bone screws for use in thescrewdriver-type bone anchor inserter of FIG. 1c. Several different bonescrew embodiments are shown, in accordance with the present invention.

FIG. 1e is a right cross-sectional view of a spring loaded C-shapedinserter, having an alternative spring mechanism.

FIG. 2 is a perspective view of a catheter inserted into the bladder ofa patient in accordance with the method of the present invention, with aphysician's (or health care worker's) two fingers partially insertedinto a woman's vagina.

FIG. 3 is a perspective view of the hand of the physician pressing theanterior vaginal wall of a patient against the posterior of her pubicbone, according to the present method (again with the catheter inplace).

FIG. 4 is a perspective view of the bone anchor non linear inserter (inthis case, a C-shaped inserter) inserted into the vaginal canal, withthe anchor housing pressing the anterior vaginal wall of the patientagainst her pubic bone. Notice that the physician's hand, which is usedfor triggering the mechanism of the inserter, is outside of the vaginaand that the physician can pull the inserter against the resistive forceof the pubic bone. An enlarged inset cross-sectional view is provided ofthe insertion step of the bone anchor into the pubic bone.

FIG. 5 is a perspective view of the hands of the physician tying thesuture threads affixed to the bone anchors (the bone anchors havingfirst been ejected or screwed, and implanted into the patient's pubicbone).

FIG. 6 is a bottom, front and left side perspective view of one form ofa bone anchor used with the stapler/bone anchor inserter describedherein.

FIG. 7 is a front view of the stapler type bone anchor shown in FIG. 6which can be used with the staple inserter. In this figure, one exampleof a bone anchor with an offset tip is shown, i.e. a bone anchor inwhich the central, longitudinal axis of the tip is offset from thecentral, longitudinal axis of the bone anchor's shaft or body. An offsettip can be provided to a staple type bone anchor or to a screw type boneanchor.

FIG. 8 is a front view of the curved shape that a bone anchor (e.g. thatshown in FIGS. 6 or 7) can achieves after insertion into bone, aconsequence of it having been formed of shape memory alloy and thetemperature of the staple having changed to its state changingtemperature.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PREFERRED EMBODIMENTS

The present invention relates to an improved inserter device (whether astapler or screw inserter) for inserting a bone anchor (whether stapleor screw) into a patient. The inserter is shaped in a “C” shaped designwhich allows the physician's pulling force to press the staple or screwinto the bone before and during ejection or screwing of a bone anchor.As a consequence, the physician is able to use a pulling force againstthe resistive force of the pubic bone rather than a pushing forceagainst the recoil of the inserter. The device also allows the physicianto use the weight of a patient's body as counterbalancing leverage tominimize recoil of the staple during ejection of a staple into thepatient's body. In addition, the novel geometry of the inserter allowsthe physician to hold the inserter and perform a per vaginal procedurewith one hand out of the vagina.

As shown in FIGS. 1a and 1 b, a stapler or bone anchor inserter 10 isdisclosed having a handle 15, trigger 20, anchor housing 25 and ananchor shield 30. Handle 15 is attached to body 55 of the bone anchorinserter 10. Body 55 is curved such that when attached to the handle 15the two components form a “C” shaped apparatus. The inserter can beformed as a V-shape or another non-linear configuration.

In use, a drive pin (not shown, but located within the body) forces theanchor 35 (See FIG. 6, without suture thread shown, for ease ofillustration) out of anchor housing 25, which is part of barrel 50 (seeFIG. 1B) of the stapler 10. The stapler or bone anchor inserter 10 maybe made of any suitable material, for example, stainless steel whichmeets surgical instrument standards. An internal spring mechanism (notshown) is in mechanical contact with the ejector pin (which is placed incontact with the bone anchor or staple). Upon the activation of thetrigger 20, the ejector pin comes into contact with the bone anchor orstaple 35, providing the forcible ejecting, pushing and implanting ofthe bone anchor or staple 35, with attached suture thread, into bone.The ejection mechanism is activated by the trigger 20 which can beprovided with a safety release or lock-out 42 to prevent accidental,premature staple discharge.

The tail end of the anchor 35 (best seen in FIGS. 6-8) is held in anearly straight configuration within anchor housing 25 until ejection.The anchor housing 25 is attached to the inserter 10 prior to use,remains attached to the inserter during anchor insertion and, afterinsertion of the bone anchor, is disposable. A retractable anchor shield30 surrounds and protects the sharp conical front end of the anchor, toease insertion. The bone anchor 35 (the specific anchor 44 is shown inFIGS. 6-8) is implanted into the bone without pre-drilling of a hole inthe patient's bone. After cocking the internal spring mechanism using aloading key 40, which is placed into and rotated within loading socket45, and attaching a bone anchor housing 25 (with a sutured anchor 35 or44), the bone anchor inserter 10 is ready for use. The spring mechanismstores the mechanical energy necessary to eject and insert the anchorinto bone. In one preferred embodiment, this is approximately 2.95Joule±10%.

FIG. 1c illustrates a C-shaped bone anchor driver in a shape allowingrotational insertion of a bone screw into a bone through a body orificesuch as the vagina. The inserter consists of a handle 70 having abattery-operated rotating motor 75 with a switch 80 to controloperation. The motor's rotational movements are linked to a gear box(gear 81 and gear to shaft adapter 83) to allow more torque. Therotation is transferred from the gear box through the inserter device tothe screw adapter 90, via a flexible shaft 95, a flexible shaft guide 97may be provided, as well, if desired.

The anchor is connected to screw adapter 90, which is at the second endof the inserter, the end opposite the handle. The anchor or screw isdisconnected once the screw is implanted into the bone surface. Thescrew protector or retractable shield 100 shields the sharp tip of thescrew until it is well positioned, so as not to accidentally damage thepatient's tissue. Once the inserter is well positioned, pulling thehandle 70 retracts the spring-biased screw protector or retractableshield 100 thereby allowing the screw's sharp tip to penetrate the softtissue. In another embodiment, the screw protector or retractable shield100 may have a rough edge surface, or small pins or sharp tips to holdthe soft tissue (such as vaginal mucosa) and to prevent surroundingtissue rotation as the anchor screw rotates and penetrates the softtissue and into the bone. Clearly, then, depressing switch 80 activatesthe motor 75 which drives the flexible shaft 95 connected to the screwadaptor 90. This causes a screw (see FIGS. 1D) to become embedded intothe bone.

FIG. 1e shows an alternative, spring-loaded C-shaped inserter, having adifferent spring mechanism to that shown in FIGS. 1a & 1 b. The inserterhas a two spring mechanism which allows the user to impart more energyand impact to the anchor during implantation into the bone. At the sametime, this inserter has the significant advantage that the two springdesign results in cancellation of the rotational movement that theinserter may have during release. This results in a more stable anchorinsertion.

This alternative inserter embodiment utilizes a hammer 200 which impactsand ejects an anchor into a bone. When safety 205 is not in placeblocking the movement of connecting rod 210, second spring 215 canexpand outward from its compressed state against second weight 220 toforce second rod 225 forward to rotate connecting rod 210. Connectingrod 210 is connected to both second rod 225 and to main rod 230.Rotation of the connecting rod 210 in the counterclockwise position bysecond rod 225, as shown in FIG. le, moves main rod 230 away from itsposition up against main weight 235 which causes hammer 200 to impact abone anchor.

More specifically, while main rod 230 is forced against main weight 235,the hammer 200 is maintained in a stationary position and primed forsubsequent movement to eject a bone anchor held in recess 260. Mainspring 240 is connected to main weight 235, with main weight 235connected to hammer 200. A friction disk 245 is provided above mainspring 240. A hammer guide 250 is provided around a portion of thehammer 200, as shown in FIG. 1e. Before activation of the inserter, mainspring 240 is maintained in a compressed position. Movement of main rod230 away from main weight 235 allows main spring 240 to expand outward,forcing main weight 235 and hammer 200 downward. The release of theenergy stored in main spring 240 thus forces hammer 200 downward toimpact and eject a bone anchor out of recess 260 and into a bone.

The method of the present invention is shown in FIGS. 2-5. With thepatient in lithotomy position, the surgical area and the vagina arecleaned and disinfected. A Foley catheter is inserted inside thebladder, and the balloon is inflated with approximately 10-20 cc ofwater. The catheter is then pulled backwardly to locate the balloon justabove the bladder neck as shown in FIG. 2.

The catheter (within the urethra) and the balloon at the bladder neckare palpated by the physician's finger tips. Pressing the fingers upwardand forward, the anterior vaginal wall is pressed against the posteriorpubic bone surface, as shown in FIG. 3.

The bone anchor inserter (whether a stapler/impact or a screwdriver-typeinserter) is then inserted into the vagina (see FIG. 4) near the bladderneck and approximately 2 cm. to the side of the urethra. The inserter ispulled against the pubic bone. Notice that the triggering hand of thephysician is external to the vagina and that the force applied by thephysician is one of pulling against the resistive force of the pubicbone. The tip of the bone anchor 35 touches and penetrates the vaginalwall and enters the cortex of the pubic bone.

Thus, once the inserter is stable and properly positioned in the vagina,the trigger 20 (or switch 80, for the screw inserter of FIG. 10) ispulled and the bone anchor 25 penetrates and fixates within the bone.When the end of the inserter 10 is under the pubic bone, and pressedagainst it, the physician pulls up on the handle 15 of the stapler orbone anchor inserter 10. By doing so, the physician lifts the anchor 35or screw 120 and anchor housing 25 or screw adaptor 90 against the pubicbone. A portion of the weight of the patient resists the lifting of theinserter, pressing against it firmly. As a result, the lifting of thestapler or bone anchor inserter 10 is performed against some of theweight of the patient, ensuring a firm and effective contact of theanchor tip with the pubic bone. Mechanically, it is easier for thephysician to pull on the inserter with his or her hand outside of thevagina than for the physician to have his or her triggering hand withinthe vagina and pushing the inserter against the pubic bone. Thepenetration of the tip of the bone anchor into the bone cortex beforeejection or screwing further increases the stability of the ejectioninto the pubic bone. The use of the C-shaped inserter allows at leastpart of the patient's weight to counterbalance the recoil of the springmechanism. The patient's body weight, along with the inserter's shape,provides the physician with suitable leverage for ensuring penetrationof the anchor 35 or screw 120 into the pubic bone. This is especiallyimportant in the use of the present bone anchor device which, in thecase of the ejected anchor, seeks to avoid pre-drilling of a hole,followed by anchor insertion.

Releasing the safety 42 first and then pressing the trigger 20 of thedevice activates the inserter spring mechanism (not shown) which ejectsthe anchor 35 to a prescribed depth within the bone (e.g. 2.5 mm) sothat no portion of the anchor protrudes from the bone surface. Althoughthe end of the inserter will experience a reaction force when the stapleis ejected, the weight of the patient, pressing downward against theinserter end (anchor housing 25 and anchor shield 30) combined with theforce exerted by the physician by pulling the handle 15 of the boneanchor inserter 10 upward (so that the end of the inserter is forcedagainst the weight of the patient and the penetration of the tip of theanchor into the pubic bone before ejection) result in a firm and solidcontact between the inserter and the pubic bone during and through theinsertion process, minimizing any problems of insertion associated withstapler recoil.

Two to four anchors are preferably inserted into the patient. Boneanchors are inserted on each side of the urethral axis or parallel alongeach side of the posterior aspect of the superior pubic bone ramus,lateral to the symphysis pubis. When four bone anchors are used, twobone anchors are inserted on each side of the urethral axis or parallelalong each side of the posterior aspect of the superior pubic ramus,about 2 cm. lateral to the symphysis pubis. Each pair of two boneanchors is inserted with the two bone anchors in a pair approximately 2cm. apart. Cystoscopy is then performed to verify that there are nobladder or urethral perforations.

The suture threads extending from the anchors are then tied. Forexample, when inserting four bone anchors, four sets of suture threadsshould protrude from the vaginal wall. The suture threads are tied fromone bone anchor to the other, ipsilaterally on each side of the urethra,as shown in FIG. 5. They may be tied either above the vaginal mucosa orbelow the vaginal mucosa (using a deshamp) with or without vaginaldissection. The tie may be left as is or pushed beneath the mucosa.

Suprapubic or Foley urethral catheterization is then performed. Thesuprapubic catheter is to remain until complete bladder emptying isachieved by normal urination. Prophylactic antibiotic is administeredperioperatively. Physical strain and lifting by the patient is to beavoided for approximately 2-3 months.

In one recommended embodiment, the bone anchor can be made of a singlepiece of a shape memory alloy, such as the nickel-titanium alloy calledNitinol. One form of bone anchor, for example, which can be used withthe present invention, has a conical front end 46 (See FIGS. 6-8) withdiameters ranging from 1.9-2.4 mm, and a tail end with a nearlyrectangular cross-section. The tail portion is preferably 6.0 mm longwith a width that ranges from 1.9-2.4 mm and a thickness of about 0.6mm. The anchor tail 44 contains two holes 48 and 50 which are used forthreading the suture. An example of a suture thread which can be used inthe bone anchor is sterile polypropelene monofilament No. 1. The boneanchor is depicted in FIGS. 6 through 8. According to the preferredembodiment of the bone anchor 35, the longitudinal axis of the tail endis offset from the center axis of the conical tip 46. This is best seenin FIGS. 7 and 8.

Within the bone medulla, the bone anchor 35 soon heats to bodytemperature, changing by shape memory alloy, for example, from astraight to a curved shape, i.e., the longitudinal axis of the anchorchanges, after insertion. This is shown in FIG. 8. According to onepreferred embodiment, the end of the tail and the rear end of theconical tip, after heating of the bone anchor sufficient to change itsshape, will subtend an angle of about 75°±16° (as seen in FIG. 8). Thischange of shape is because of the fabrication of the anchor from shapememory alloy. This curved shape fixes the anchor within the bone andinhibits the inadvertent removal of the anchor. Pulling on the suture,which is connected to the anchor 35, causes the anchor to rotate andfurther fixate in the bone. The reformation of the anchor to its curvedshape (the shape it had prior to straightening by being held in theanchor housing 35) and rotation, together, prevent the anchor fromexiting through the entrance path provided into the bone. The smallprofile and sharpness of the anchor tip 46 allow easy insertion insidethe bone with minimal damage to the bone surface.

Thus, the present invention provides an apparatus and method which (inthe anchor ejection mode) does not require pre-drilling of the bone orsoft tissue dissection to insert the bone anchor into the bone.Similarly, the bone anchor does not require cement or other fixative toremain in place.

The bone anchor and bone anchor inserter are supplied sterile. As thebone anchor inserter is a multiple use device, the inserter (and itsloading key) should, of course, be cleaned and sterilized before eachnew patient procedure. Cleaning is accomplished by washing and rinsingthe inserter and loading key with water and a liquid detergent, whilescrubbing with a flexible brush to completely remove all traces ofblood. The inserter and loading key should be rinsed thoroughly withwater to remove detergent residues. Panels in the inserter body allowaccess for cleaning. Once cleaned, the inserter and loading key may becloth or air dried. The inserter and loading key may be sterilized byheat or steam autoclave, or gas (EtO), in accordance with hospitalprocedures for sterilization of stainless steel surgical instruments.

Various different types of bone screws 120 can be used in accordancewith the present invention. As shown in FIG. 1d(1), a bone screw isdisclosed having a conical tip 110 and a screw body 115. The diameter ofeach of the screw threads 128 (the grooves, recesses or indentations inthe material of the screw) is constant along the screw body. The suture125 is attached at a hole in the end 127 of the bone screw.

FIG. 1d(2) shows a bone screw 120 with a more tapered conical tip 130and a screw body 135. In this version, the diameter of the screw threads140 vary. The diameters of the screw threads 140 increase from smalldiameters near the apex of the conical tip to greater diameters near thescrew body 135. The screw threads 140 can be located on all or a portionof the screw body as well, if desired. The suture 150 is attachedthrough a hole in the end 147 of the screw.

FIG. 1d(3) is similar to FIG. 1d(1). In this FIG., however, the sutureis shown attached through a hole in the middle 152 of the bone screw.

FIG. 1d(4) shows a bone screw 120 in which the screw threads or groovesare formed by wrapping spring wire 156 around a solid body. The body hasa leading tip 170 and a shaft 172, of smaller relative cross section. Atrailing end 174 with a hole is provided for attaching the suture thread176. The spring wire is wrapped on the shaft 172 and maintained betweenleading tip 170 and the trailing end 174.

FIG. 1d(5) shows a bone screw similar to that in FIG. 1d(4). In thisscrew, leaf springs 158 are provided. Leaf springs 158 are initiallyflattened against the side surface of the bone screw, i.e., when thescrew is inserted into the bone. Upon insertion, however, the leafsprings 158 expand outward from a compressed to a non-compressed state(due to the elasticity which is characteristic of a spring) to providegreater anchoring of the bone screw within the bone.

FIG. 1d(6) discloses a bone screw in which the screw threads or groovesare formed by wrapping a spring plate 163 around the screw body or shaftof the screw. Here, too, the spring plate is held between the leadingtip and the trailing end.

The bone screw is typically made of a medical grade alloy such asStainless Steel 316. Its sharp tip and small diameter allows for itspenetration through the vaginal wall and the periosteum, withoutpre-drilling a hole. As the screw is rotated by the inserter, which maybe linear or C-shaped, it further enters the bone until it reaches aprescribed depth within the bone. The screw then automaticallydisconnects from the rotating inserter shaft. The medical technique ofinserting a bone screw into the pubic bone through the vagina for thepurposes of bladder neck suspension is also within the scope of thepresent invention, as is the bone screw inserter.

Having described this invention with regard to specific embodiments, itis to be understood that the description is not meant as a limitationsince further variations or modifications may be apparent or may suggestthemselves to those skilled in the art. It is intended that the presentapplication cover such variations and modifications as fall within thescope of the appended claims.

We claim:
 1. A medical inserter device for installing a bone anchor withattached suture into a patient, comprising: a handle, said handle beingat a first end of said medical inserter device; a body, said body beingattached to said handle, said body and said handle together forming anon-linear shape, an anchor housing located at a second end of saidbody, opposite to said first end, for holding a bone anchor duringinstallation; a retractable shield proximate said anchor housing; apower source in communication with said anchor housing for providingpower to install said bone anchor; and, a trigger in communication withsaid power source.
 2. A medical inserter device as claimed in claim 1,wherein said body and said handle together form a C shape.
 3. A medicalinserter device as claimed in claim 1, wherein said body and said handletogether form a V shape.
 4. A medical inserter device as claimed inclaim 1, wherein said inserter device is a medical stapler for forciblyejecting and implanting a bone anchor into the bone of a patient.
 5. Amedical inserter device as claimed in claim 1, wherein said inserterdevice is a screw driving device for screwing a bone anchor into thebone of a patient.